The castle played a minor part in the English Civil War, but after Deddington's strategic importance waned, the site lay vacant for many decades, used only for grazing and forestry.

Odo's estates in England were seized following a failed rebellion against William II in 1088, and Deddington Castle was taken back into royal control.

After de Chesney's death, his descendants fought for control of the castle in the royal courts, and it was temporarily seized several times by King John at the start of the 13th century.

Following the discovery of medieval remains and a subsequent archaeological investigation, these plans were abandoned and the western half of the castle became a local park.

In the 21st century, English Heritage manage the inner bailey, the eastern half remaining in use for farming, and the site as a whole is protected under UK law as a scheduled monument.

At this time Deddington was one of the largest settlements in the county of Oxfordshire, and the site of the castle had been previously occupied by the Anglo-Saxons, who may have used the location to administer one of their landed estates.

[4] The castle was probably built to act as the caput, or administrative centre, of his lands in the region, and may have also been intended to quarter a large military force in the event of an Anglo-Saxon revolt.

[5] The castle was positioned on the east side of the main part of the settlement at the time, at the opposite end of the village to the church, on a spur overlooking a nearby stream.

[8] The castle's layout was unusual for the region during this period, where the fortifications built by the Normans were typically smaller ringwork designs, and it highlighted both the strategic importance of the location and the power of its builder.

[8] It is uncertain exactly why the new earthworks were constructed, but it may have been to strengthen the fortification in response to either the threatened invasion of Duke Robert of Normandy in 1101, or alternatively to the sinking of the White Ship and the subsequent dynastic crisis in 1120.

[13] By 1157, the castle was owned by William de Chesney, an Anglo-Norman lord who had supported King Stephen in the region during the civil war of the Anarchy, and then Henry II after the peace in 1154.

[14] William rebuilt much of the castle, constructing a strong stone curtain wall around the inner bailey, 2 metres (6 ft 7 in) thick and made from mortared ironstone rubble.

[22] Although the village had grown to become a borough, with new, planned streets spreading westwards away from the castle, it was eclipsed economically by the nearby, newer centre of Banbury.

[26] He was taken south by Aymer de Valence, the Earl of Pembroke, who imprisoned Gaveston at Deddington on 9 June while he left to visit his wife.

[27] During the 14th century the interior of the castle continued to be inhabited, but in a manner that archaeologist Richard Ivens likens to "squatting": the upper levels of the tower were abandoned and wood burnt along the inside of the walls in a crude fireplace.

[21] The parish council intended to build tennis courts in the inner bailey of the castle, but when work began, medieval pottery and roof tiles were unearthed by the builders.

[32] Construction work was halted and the Ashmolean Museum in Oxford sponsored an archaeological investigation by Edward Jope and Richard Threlfall that continued until 1953.